Identification of candidate genes that specifically regulate subcutaneous and intramuscular fat deposition using transcriptomic and proteomic profiles in Dingyuan pigs.

Subcutaneous fat and intramuscular fat (IMF) deposition are closely related to meat production and pork quality. Dingyuan pig, as a native pig breed in China, low selection leads to obvious genetic and phenotypic differences in the population. Individuals with extreme fat content in the population are ideal models for studying the mechanism of fat deposition. In this study, we used RNA-Seq and tandem mass tags-based (TMT) proteomics to analyze the key pathways and genes that specifically regulate subcutaneous fat and IMF deposition in Dingyuan pigs. We identified 191 differentially expressed genes (DEGs) and 61 differentially abundant proteins (DAPs) in the high and low back fat thickness (HBF, LBF) groups, 85 DEGs and 12 DAPs were obtained in the high and low intramuscular fat (HIMF, LIMF) groups. The functional analysis showed that the DEGs and DAPs in the backfat groups were mainly involved in carbohydrates, amino acids, and fatty acids metabolism, whereas the IMF groups were involved in the insulin pathway, longevity, and some disease-related pathways. We found 40 candidate genes that might tissue-specifically lipids deposition for subcutaneous and intramuscular fat. Our research provides theoretical reference materials for the improvement of fat deposition traits of local pig breeds in my country.

Early postnatal interactions between beige adipocytes and sympathetic neurites regulate innervation of subcutaneous fat.

While beige adipocytes have been found to associate with dense sympathetic neurites in mouse inguinal subcutaneous white fat (iWAT), little is known about when and how this patterning is established. Here, we applied whole-tissue imaging to examine the development of sympathetic innervation in iWAT. We found that parenchymal neurites actively grow between postnatal day 6 (P6) and P28, overlapping with early postnatal beige adipogenesis. Constitutive deletion of Prdm16 in adipocytes led to a significant reduction in early postnatal beige adipocytes and sympathetic density within this window. Using an inducible, adipocyte-specific Prdm16 knockout model, we found that Prdm16 is required for guiding sympathetic growth during early development. Deleting Prdm16 in adult animals, however, did not affect sympathetic structure in iWAT. Together, these findings highlight that beige adipocyte-sympathetic neurite communication is crucial to establish sympathetic structure during the early postnatal period but may be dispensable for its maintenance in mature animals.

Mammals have two types of fatty tissue: white fat that mainly stores energy, and brown and beige fat, also known as thermogenic fat, which burns energy to generate heat. In humans, brown fat is associated with potent anti-obesity and anti-diabetes effects. A better understanding of how this type of fat develops and functions could lead to therapeutic strategies to treat these conditions. Adult human brown fat is similar to rodent inducible brown fat, also known as beige fat. In adult mice, beige fat cells need stimulation from the environment to form. Cold can lead to the generation of beige fat cells by activating a part of the nervous system known as the sympathetic nervous system. In order for this cold-induced formation of beige fat cells to take place, nerves from the sympathetic nervous system must first innervate the fatty tissue. Beige fat cells themselves are important for establishing this innervation, but it was not well understood when and how this occurs. To study the role of beige fat cells in the establishment of nerve innervation, Chi et al. used genetically modified mice whose beige fat cells are removed when they are treated with an antibiotic called doxycycline. If mice that had not been genetically modified were treated with doxycycline, they developed beige fat cells soon after birth, and these cells shortly became densely innervated by the sympathetic nervous system. However, if the mutant mice were treated with doxycycline around birth, these mice could not make beige fat cells during the treatment and failed to develop dense innervation even when they grew older. These results showed that beige fat cells that form soon after birth are necessary to establish sympathetic nervous system innervation. But are beige fat cells required to maintain this innervation as the mice grow older? To test this, Chi et al. removed them after the innervation was fully established. These mice maintained their innervation, showing that beige fat cells appear to only be required during the establishment of innervation. Understanding how the sympathetic nervous system establishes its connection to fat so cold can stimulate beige fat formation is a first step to finding new treatments for conditions such as diabetes or obesity. Exploring the timing that underlies the interactions between the sympathetic nervous system and beige fat cells may provide therapeutic targets in this direction.

Effect of early determinants on adolescent fat-free mass: RPS cohort of São Luís - MA.

OBJECTIVE: To analyze the effects of early determinants on adolescent fat-free mass. METHODS: A cohort study with 579 adolescents evaluated at birth and adolescence in a birth cohort in São Luís, Maranhão. In the proposed model, estimated by structural equation modeling, socioeconomic status (SES) at birth, maternal age, pregestational body mass index (BMI), gestational smoking, gestational weight gain, type of delivery, gestational age, sex of the newborn, length and weight at birth, adolescent socioeconomic status, "neither study/nor work" generation, adolescent physical activity level and alcohol consumption were tested as early determinants of adolescent fat-free mass (FFM). RESULTS: A higher pregestational BMI resulted in higher FFM in adolescence (Standardized Coefficient, SC = 0.152; p < 0.001). Being female implied a lower FFM in adolescence (SC = -0.633; p < 0.001). The negative effect of gender on FFM was direct (SC = -0.523; p < 0.001), but there was an indirect negative effect via physical activity level (SC = -0.085; p < 0.001). Women were less active (p < 0.001). An increase of 0.5 kg (1 Standard Deviation, SD) in birth weight led to a gain of 0.25 kg/m2 (0.106 SD) in adolescent FFM index (p = 0.034). Not studying or working had a negative effect on the adolescent's FFM (SC = -0.106; p = 0.015). Elevation of 1 SD in the adolescent's physical activity level represented an increase of 0.5 kg/m2 (0.207 SD) in FFM index (p < 0.001). CONCLUSIONS: The early determinants with the greatest effects on adolescent FFM are gender, adolescent physical activity level, pregestational BMI, birth weight and belonging to the "neither-nor" generation.

Dynamic changes in chromatin accessibility, altered adipogenic gene expression, and total versus de novo fatty acid synthesis in subcutaneous adipose stem cells of normal-weight polycystic ovary syndrome (PCOS) women during adipogenesis: evidence of cellular programming.

BACKGROUND: Normal-weight polycystic ovary syndrome (PCOS) women exhibit adipose resistance in vivo accompanied by enhanced subcutaneous (SC) abdominal adipose stem cell (ASC) development to adipocytes with accelerated lipid accumulation per cell in vitro. The present study examines chromatin accessibility, RNA expression and fatty acid (FA) synthesis during SC abdominal ASC differentiation into adipocytes in vitro of normal-weight PCOS versus age- and body mass index-matched normoandrogenic ovulatory (control) women to study epigenetic/genetic characteristics as well as functional alterations of PCOS and control ASCs during adipogenesis. RESULTS: SC abdominal ASCs from PCOS women versus controls exhibited dynamic chromatin accessibility during adipogenesis, from significantly less chromatin accessibility at day 0 to greater chromatin accessibility by day 12, with enrichment of binding motifs for transcription factors (TFs) of the AP-1 subfamily at days 0, 3, and 12. In PCOS versus control cells, expression of genes governing adipocyte differentiation (PPARγ, CEBPα, AGPAT2) and function (ADIPOQ, FABP4, LPL, PLIN1, SLC2A4) was increased two-sixfold at days 3, 7, and 12, while that involving Wnt signaling (FZD1, SFRP1, and WNT10B) was decreased. Differential gene expression in PCOS cells at these time points involved triacylglycerol synthesis, lipid oxidation, free fatty acid beta-oxidation, and oxidative phosphorylation of the TCA cycle, with TGFB1 as a significant upstream regulator. There was a broad correspondence between increased chromatin accessibility and increased RNA expression of those 12 genes involved in adipocyte differentiation and function, Wnt signaling, as well as genes involved in the triacylglycerol synthesis functional group at day 12 of adipogenesis. Total content and de novo synthesis of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1), and oleic (C18:1) acid increased from day 7 to day 12 in all cells, with total content and de novo synthesis of FAs significantly greater in PCOS than controls cells at day 12. CONCLUSIONS: In normal-weight PCOS women, dynamic chromatin remodeling of SC abdominal ASCs during adipogenesis may enhance adipogenic gene expression as a programmed mechanism to promote greater fat storage.

Gain and loss of subcutaneous and abdominal adipose tissue depot mass of German Holstein dairy cows with different body conditions during the transition period.

Subcutaneous adipose tissue (SCAT) and abdominal adipose tissue (AAT) depots are mobilized during the fresh cow period (FCP) and early lactation period (ELP) to counteract the negative energy balance (NEB). Earlier studies suggested that fat depots contribute differently to lipomobilization and may vary in functionality. Differences between the adipose depots might influence the development of metabolic disorders. Thus, the gain and loss of subcutaneous and abdominal adipose depot masses in Holstein cows with lower and higher body condition (mean body condition scores: 3.48 and 3.87, respectively) were compared in the period from d -42 to d 70 relative to parturition in this study. Animals of the 2 experimental groups represented adequately conditioned and overconditioned cows. Estimated depot mass (eDM) of SCAT, AAT, retroperitoneal, omental, and mesenteric adipose depots of 31 pluriparous German Holstein cows were determined via ultrasonography at d -42, 7, 28, and 70 relative to parturition. The cows were grouped according to the eDM of SCAT on d -42 [low body condition (LBC) group: n = 16, mean eDM 8.6 kg; high body condition (HBC) group: n = 15, mean eDM 15.6 kg]. Average daily change (prepartum gain and postpartum loss) in depot masses during dry period (DP; from d -42 to d 7), FCP (d 7 to d 28), and ELP (d 28 to d 70) were calculated and daily dry matter intake and lactation performance recorded. Cows of this study stored about 2 to 3 times more fat in AAT than in SCAT depots. After parturition, on average more adipose tissue mass was lost from the AAT than the SCAT depot (0.23 kg/d vs. 0.14 kg/d). Cows with high compared with low body condition had similar gains in AAT (0.33 kg/d) and SCAT (0.14 kg/d) masses during the DP but mobilized significantly more adipose tissue mass from both depots after calving (AAT, HBC vs. LBC: 0.30 vs. 0.17 kg/d; SCAT, HBC vs. LBC: 0.19 vs. 0.10 kg/d). Correlation analysis indicated a functional disparity between AAT and SCAT. In the case of AAT (R2 = 0.36), the higher the gain in adipose mass during DP, the higher the loss in FCP, but this was not the case for SCAT. During FCP, a greater NEB resulted in greater loss of mass from SCAT (R2 = 0.18). In turn, greater mobilization of SCAT mass led to a higher calculated feed efficiency (R2 = 0.18). However, AAT showed no such correlations. On the other hand, during ELP, loss of both SCAT and AAT mass correlated positively with feed efficiency (R2 = 0.35 and 0.33, respectively). The results indicate that feed efficiency may not be an adequate criterion for performance evaluation in cows during NEB. Greater knowledge of functional disparities between AAT and SCAT depots may improve our understanding of excessive lipomobilization and its consequences for metabolic health and performance of dairy cows during the transition period.

Developmental programming: Transcriptional regulation of visceral and subcutaneous adipose by prenatal bisphenol-A in female sheep.

BACKGROUND: Bisphenol-A (BPA) exposure is widespread and early life exposure is associated with metabolic syndrome. While visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) are implicated in the development of metabolic syndrome, the adipose depot-specific effects of prenatal BPA treatment are poorly understood. OBJECTIVE: To determine the impact of prenatal BPA exposure on genome-wide gene expression of VAT and SAT depots. METHODS: RNA sequencing was performed on SAT and VAT from 21-month old control and prenatal BPA-treated female sheep. Gene expression and pathway differences between SAT and VAT depots with or without prenatal BPA-treatment and the effect of prenatal BPA treatment on each depot were tested. RESULTS: There were 179 differentially expressed genes (padjusted < 0.05, log2-fold change >2.5) between SAT and VAT. Development and immune response pathways were upregulated in SAT, while metabolic pathways were upregulated in VAT. These adipose depot-specific genes and pathways were consistent with prenatal BPA-treatment. In SAT, BPA-treatment resulted in differential expression of 108 genes (78% upregulated with BPA) and altered pathways (immune response downregulated, RNA processing upregulated). In contrast in VAT, BPA-treatment differentially expressed 4 genes and upregulated chromatin and RNA processing pathways. CONCLUSION: Prenatal BPA-treatment induces adult depot-specific alterations in RNA expression in inflammation, RNA processing, and chromatin pathways, reflecting the diverse roles of SAT and VAT in regulating lipid storage and insulin sensitivity. These adipose tissue transcriptional dysregulations may contribute to the metabolic disorders observed in prenatal BPA-treated female sheep.

Subcutaneous Adipose Tissue in Female Volleyball Players: Is It Related with Performance Indices?

The aim of the present study was to examine subcutaneous adipose tissue distribution in female volleyball players with regards to (a) variation by anatomical site, (b) differences among age groups and playing positions, and (c) physiological characteristics associated with performance. Participants were adolescent (n = 89, age 15.6 ± 0.9 years, mean ± standard deviation) and adult female volleyball players (n = 78, 24.8 ± 5.3 years), who performed a series of anthropometric and performance tests including skinfold thickness in 10 sites, Abalakov jump (AJ) and handgrip test (HG). Chin had the smallest thickness, and iliac crest and abdomen the largest. The largest correlations of skinfold thickness were shown with regards to AJ ad HG. Coefficient of variations in skinfold thickness correlated with performance indices with small magnitude. Triceps and chin were the most frequent predictors of performance indices. The anatomical site of skinfold was near the active muscle groups related to performance in HG. In conclusion, performance indices such AJ and HG were related with thickness of specific skinfolds and with the variation of thickness by anatomical site (i.e., the less the variation, the better the performance). Considering the relevance of specific skinfolds (e.g., triceps and chin) for performance, their further use would be recommended for purposes of training monitoring, volleyball players' selection and talent identification.

Effect of early determinants on adolescent fat-free mass: RPS cohort of São Luís - MA

ABSTRACT OBJECTIVE: To analyze the effects of early determinants on adolescent fat-free mass. METHODS: A cohort study with 579 adolescents evaluated at birth and adolescence in a birth cohort in São Luís, Maranhão. In the proposed model, estimated by structural equation modeling, socioeconomic status (SES) at birth, maternal age, pregestational body mass index (BMI), gestational smoking, gestational weight gain, type of delivery, gestational age, sex of the newborn, length and weight at birth, adolescent socioeconomic status, "neither study/nor work" generation, adolescent physical activity level and alcohol consumption were tested as early determinants of adolescent fat-free mass (FFM). RESULTS: A higher pregestational BMI resulted in higher FFM in adolescence (Standardized Coefficient, SC = 0.152; p < 0.001). Being female implied a lower FFM in adolescence (SC = −0.633; p < 0.001). The negative effect of gender on FFM was direct (SC = −0.523; p < 0.001), but there was an indirect negative effect via physical activity level (SC = −0.085; p < 0.001). Women were less active (p < 0.001). An increase of 0.5 kg (1 Standard Deviation, SD) in birth weight led to a gain of 0.25 kg/m2 (0.106 SD) in adolescent FFM index (p = 0.034). Not studying or working had a negative effect on the adolescent's FFM (SC = −0.106; p = 0.015). Elevation of 1 SD in the adolescent's physical activity level represented an increase of 0.5 kg/m2 (0.207 SD) in FFM index (p < 0.001). CONCLUSIONS: The early determinants with the greatest effects on adolescent FFM are gender, adolescent physical activity level, pregestational BMI, birth weight and belonging to the "neither-nor" generation.

Short communication: Adipocyte sizes in the digital fat pad and their relationship to body condition in dairy cows.

Lameness and body condition are closely related. Recent studies have shown that cows with low body condition score (BCS) have a greater risk for developing lameness than cows with higher BCS. Among other reasons, this relationship might be related to the reduced thickness of the digital fat cushion in lean cows. The digital cushion is not a homogeneous structure but consists of different fat pads and connective tissue. We hypothesized that either high or low BCS will result in concordant adipocyte sizes in the fat pads of the digital cushion and subcutaneous tailhead fat irrespective of the localization of the latter. Right front claws were collected from 18 Holstein Friesian cows. Cows were selected according to their BCS: 9 cows with BCS <3 (low BCS) and 9 cows with BCS ≥3 (high BCS). After dissecting the horn capsule of the lateral claw, samples of the axial and abaxial fat pads were prepared for histomorphological examinations (adipocyte size measurement) and protein abundance of vascular endothelial growth factor A (VEGF-A) via Western blotting. In addition, fat samples were excised from the tailhead of all cows and used for the same purposes. Adipocyte size in tailhead fat was greater in high-BCS than in low-BCS cows. Similar differences between the BCS groups were apparent for adipocytes from the axial fat pad, although adipocytes in tailhead fat were larger than those in the digital cushion. In contrast to that in the axial fat pad and tailhead fat, adipocyte size in the abaxial fat pad was similar in cows from both BCS groups. A relationship between adipocyte size and VEGF-A protein was only confirmed for the axial fat pad, not for the other fat depots. When comparing BCS groups, differences in VEGF-A protein abundance between high-BCS and low-BCS cows were also limited to the axial fat pad, being absent in tailhead fat and the abaxial fat pad. Taken together, our results show that the fat pads from the digital cushion should not be considered uniform adipose tissue locations but rather discrete units reacting differently to fat mobilization.

Genome-wide association study of blood lipids in Indians confirms universality of established variants.

Lipids foster energy production and their altered levels have been coupled with metabolic ailments. Indians feature high prevalence of metabolic diseases, yet uncharacterized for genes regulating lipid homeostasis. We performed first GWAS for quantitative lipids (total cholesterol, LDL, HDL, and triglycerides) exclusively in 5271 Indians. Further to corroborate our genetic findings, we investigated DNA methylation marks in peripheral blood in Indians at the identified loci (N = 233) and retrieved gene regulatory features from public domains. Recurrent GWAS loci-CELSR2, CETP, LPL, ZNF259, and BUD13 cropped up as lead signals in Indians, reflecting their universal applicability. Besides established variants, we found certain unreported variants at sub-genome-wide level-QKI, REEP3, TMCC2, FAM129C, FAM241B, and LOC100506207. These variants though failed to attain GWAS significance in Indians, but largely turned out to be active CpG sites in human subcutaneous adipose tissue and showed robust association to two or more lipid traits. Of which, QKI variants showed significant association to all four lipid traits and their designated region was observed to be a key gene regulatory segment denoting active transcription particularly in human subcutaneous adipose tissue. Both established and novel loci were observed to be significantly associated with altered DNA methylation in Indians for specific CpGs that resided in key regulatory elements. Further, gene-based association analysis pinpointed novel GWAS loci-LINC01340 and IQCJ-SCHIP1 for TC; IFT27, IFT88, and LINC02141 for HDL; and TEX26 for TG. Present study ascertains universality of selected known genes and also identifies certain novel loci for lipids in Indians by integrating data from various levels of gene regulation.

Rehabilitation of Barbarine cull ewes using rosemary residues and linseed: effect on weight gain, carcass characteristics and meat quality.

The cull ewes represent an important part of sheep flock. However, this category of animal is often submitted to under nutrition leading to poor BW and skeletal carcasses. Their rehabilitation using a high energy diet can be an alternative to improve their body condition. The objective of this experiment was to study the BW gain and carcass characteristics of Barbarine cull ewes using rosemary (Rosmarinus officinalis L.) distillation residues (RR) and extruded linseed. For this, 28 ewes above 6 years old and 33±0.5 kg of BW were divided into four groups: CCC was fed 500 g of barley-straw with concentrate, RCC received 300 g of straw and 200 g of RR as basal diet with concentrate; whereas two other groups received the experimental concentrate, containing 10% of linseed, with 500 g of straw for CLC and 300 g of straw plus 200 g of RR for RLC group. At the end of experiment (90 days), all animals were slaughtered. For all ewes, the daily concentrate intake averaged 700 g; the average daily gain was 131 g and the slaughter BW 43.4 kg without significant difference between groups. Neither basal diet nor concentrate type did affect the carcass' weight, yield and composition. In addition, the organ's proportions were similar for all groups. The RR intake slightly improved muscle's protein content (P=0.03) and tended to decrease initial pH (P=0.06) and to increase meat redness (P=0.06), whereas linseed concentrate had no effect on meat color and its chemical composition. The subcutaneous fat color and firmness score relived a good quality trade for carcasses from all diets, in spite of higher yellowness and lower firmness recorded for linseed diet (P<0.05), which were moderately improved by rosemary combination with linseed. To conclude, the Barbarine cull ewes could gain up to 120 g/day in BW. The used diets permitted this BW gain without undesirable effects on carcass characteristics and meat quality. However, the study of meat fatty acid profile and antioxidant status should continue.

Genomic regions and enrichment analyses associated with carcass composition indicator traits in Nellore cattle.

The aim of this study was to estimate genetic parameters and identify genomic regions associated with carcass traits obtained by ultrasound and visual scores in Nellore cattle. Data from ~66,000 animals from the National Association of Breeders and Researchers (ANCP) were used. The variance components for backfat thickness, rump fat thickness and Longissimus muscle area (LMA) were estimated considering a linear model whereas a threshold model for body structure (BS), finishing precocity (FP) and musculature (MS) traits. The SNP solutions were estimated using the ssGBLUP approach by considering windows of 10 consecutive SNPs. Regions that accounted for more than 1.0% of the additive genetic variance were used. Genes identified within the significant windows, such as FOXA3, AP2S1, FKRP, NPASI and ATP6V1G1, were found to be related with MS, while OMA1 and FFGY with BS and FP traits. The PLTP, TNNC2 and GPAT2 genes were found in the regions associated with LMA, as well as TKT, FNDC5 and CHRND can strongly be related with fat deposition. Gene enrichment analysis revealed processes that might be directly influenced the organism growth and development. These results should help to better understand the genetic and physiological mechanisms regulating growth and body composition, muscle tissue development and subcutaneous fat expression, and this information might be useful for future genomic studies in Nellore cattle.

Pannexin 1 regulates adipose stromal cell differentiation and fat accumulation.

Pannexin 1 (Panx1) is a channel-forming glycoprotein important in paracrine signaling and cellular development. In this study, we discovered that mice globally lacking Panx1 (KO) have significantly greater total fat mass and reduced lean mass compared to wild type (WT) mice under a normal diet. Despite having higher fat content, Panx1 KO mice on a high fat diet exhibited no differences in weight gain and blood markers of obesity as compared to WT controls, except for an increase in glucose and insulin levels. However, metabolic cage data revealed that these Panx1 KO mice display significantly increased activity levels, higher ambulatory activity, and reduced sleep duration relative to their WT littermates on a high-fat diet. To uncover the cellular mechanism responsible for the increased fat content in the KO, we isolated primary cultures of adipose-derived stromal cells (ASCs) from WT and KO fat pads. In WT ASCs we observed that Panx1 protein levels increase upon induction into an adipogenic lineage. ASCs isolated from Panx1 KO mice proliferate less but demonstrate enhanced adipogenic differentiation with increased intracellular lipid accumulation, glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity, and adipokine secretion, as compared to WT ASCs. This was consistent with the increased adipocyte size and decreased adipocyte numbers observed in subcutaneous fat of the Panx1 KO mice compared to WT. We concluded that Panx1 plays a key role in adipose stromal cells during the early stages of adipogenic proliferation and differentiation, regulating fat accumulation in vivo.

Role of AMPK signalling pathway during compensatory growth in pigs.

BACKGROUND: The molecular basis of compensatory growth in monogastric animals has not yet been fully explored. Herewith, in this study we aim to determine changes in the pig skeletal muscle transcriptome profile during compensatory growth following a feed restriction period. A RNA-Seq experiment was performed with a total of 24 females belonging to a Duroc commercial line. Half of the animals received either a restricted (RE) or ad libitum (AL) diet during the first fattening period (60-125 d of age). After that, all gilts were fed ad libitum for a further ~30 d until the age of ~155 d, when animals were slaughtered and samples of gluteus medius muscle were harvested to perform RNA-Seq analyses and intramuscular fat content determination. RESULTS: During the period following food restriction, RE animals re-fed ad libitum displayed compensatory growth, showed better feed conversion rate and tended to deposit more subcutaneous fat than AL fed animals. Animals were slaughtered in the phase of accelerated growth, when RE animals had not completely compensated the performance of AL group, showing lower live and carcass weights. At intramuscular level, RE gilts showed a higher content of polyunsaturated fatty acids during the compensatory growth phase. The comparison of RE and AL expression profiles allowed the identification of 86 (ǀlog2Fold-Changeǀ > 1, padj < 0.05) differentially expressed (DE) genes. A functional categorization of these DE genes identified AMPK Signaling as the most significantly enriched canonical pathway. This kinase plays a key role in the maintenance of energy homeostasis as well as in the activation of autophagy. Among the DE genes identified as components of AMPK Signaling pathway, five out of six genes were downregulated in RE pigs. CONCLUSIONS: Animals re-fed after a restriction period exhibited a less oxidative metabolic profile and catabolic processes in muscle than animals fed ad libitum. The downregulation of autophagy observed in the skeletal muscle of pigs undergoing compensatory growth may constitute a mechanism to increase muscle mass thus ensuring an accelerated growth rate. These results reveal that the downregulation of AMPK Signaling plays an important role in compensatory growth in pigs.

On-line Ham Grading using pattern recognition models based on available data in commercial pig slaughterhouses.

The thickness of the subcutaneous fat in hams is one of the most important factors for the dry-curing process and largely determines its final quality. This parameter is usually measured in slaughterhouses by a manual metrical measure to classify hams. The aim of the present study was to propose an automatic classification method based on data obtained from a carcass automatic classification equipment (AutoFom) and intrinsic data of the pigs (sex, breed, and weight) to simulate the manual classification system. The evaluated classification algorithms were decision tree, support vector machines (SVM), k-nearest neighbour and discriminant analysis. A total of 4000 hams selected by breed and sex were classified as thin (0-10 mm), standard (11-15 mm), semi-fat (16-20 mm) and fat (>20 mm). The most reliable model, with a percentage of success of 73%, was SVM with Gaussian kernel, including all data available. These results suggest that the proposed classification method can be a useful online tool in slaughterhouses to classify hams.

Characterization of RUNX1T1, an Adipogenesis Regulator in Ovine Preadipocyte Differentiation.

Runt-related transcription factor 1 translocation partner 1 (RUNX1T1), a potential novel regulator of adipogenesis, exists in two splice variants: a long (RUNX1T1-L) and a short (RUNX1T1-S) isoform. However, there is no data showing the existence of RUNX1T1 in ovine subcutaneous fat at different stages of developmental and its role on ovine adipogenesis. Therefore, the objectives of this study were to evaluate the presence of RUNX1T1 in subcutaneous fat of five-day-old to 24-month-old sheep and to investigate the role of RUNX1T1 in ovine adipogenesis. In this study, we detected a 1829 bp cDNA fragment of RUNX1T1 which contains a 1815 bp coding sequence that encodes 602-amino acid and 14 bp of 5' untranslated region, respectively. The amino acid sequence of RUNX1T1 has 31.18⁻94.21% homology with other species' protein sequences. During fat development, the RUNX1T1 protein expression was higher in subcutaneous fat of 24-month-old Hu sheep. In addition, the expression of RUNX1T1-L mRNA decreased first, then subsequently increased during ovine preadipocyte differentiation. Knockdown of RUNX1T1-L in ovine preadipocytes promoted preadipocyte differentiation and lipid accumulation. Taken together, our data suggests that RUNX1T1 is an important functional molecule in adipogenesis. Moreover, it showed for the first time that RUNX1T1-L was negatively correlated with the ovine preadipocyte differentiation.

Deregulation of obesity-relevant genes is associated with progression in BMI and the amount of adipose tissue in pigs.

The aim of this study was to elucidate the relative impact of three phenotypes often used to characterize obesity on perturbation of molecular pathways involved in obesity. The three obesity-related phenotypes are (1) body mass index (BMI), (2) amount of subcutaneous adipose tissue (SATa), and (3) amount of retroperitoneal adipose tissue (RPATa). Although it is generally accepted that increasing amount of RPATa is 'unhealthy', a direct comparison of the relative impact of the three obesity-related phenotypes on gene expression has, to our knowledge, not been performed previously. We have used multiple linear models to analyze altered gene expression of selected obesity-related genes in tissues collected from 19 female pigs phenotypically characterized with respect to the obesity-related phenotypes. Gene expression was assessed by high-throughput qPCR in RNA from liver, skeletal muscle and abdominal adipose tissue. The stringent statistical approach used in the study has increased the power of the analysis compared to the classical approach of analysis in divergent groups of individuals. Our approach led to the identification of key components of cellular pathways that are modulated in the three tissues in association with changes in the three obesity-relevant phenotypes (BMI, SATa and RPATa). The deregulated pathways are involved in biosynthesis and transcript regulation in adipocytes, in lipid transport, lipolysis and metabolism, and in inflammatory responses. Deregulation seemed more comprehensive in liver (23 genes) compared to abdominal adipose tissue (10 genes) and muscle (3 genes). Notably, the study supports the notion that excess amount of intra-abdominal adipose tissue is associated with a greater metabolic disease risk. Our results provide molecular support for this notion by demonstrating that increasing amount of RPATa has a higher impact on perturbation of cellular pathways influencing obesity and obesity-related metabolic traits compared to increase in BMI and amount of SATa.

Associations of maternal obesity and excessive weight gain during pregnancy with subcutaneous fat mass in infancy.

BACKGROUND: Not much is known about the associations of maternal obesity and excessive gestational weight gain with body fat in infancy. OBJECTIVE: To examine the associations of maternal pre-pregnancy body mass index and gestational weight gain with infant subcutaneous fat. METHODS: In a population-based prospective cohort study among 845 mothers and their infants, we obtained maternal pre-pregnancy body mass index and measured maternal weight during pregnancy. At 1.5, 6 and 24months, we estimated infant total subcutaneous fat (sum of biceps, triceps, suprailiacal and subscapular skinfold thicknesses) and central-to-total subcutaneous fat ratio (sum of suprailiacal and subscapular skinfold thicknesses/total subcutaneous fat). RESULTS: Maternal body mass index was positively associated with higher infant body mass index from 6months onwards. Maternal body mass index was not associated with infant subcutaneous fat measures at 1.5 or 6months. A 1-standard deviation scores (SDS) higher maternal body mass index was associated with a 0.09 (95% Confidence Interval 0.01, 0.17) SDS higher infant total subcutaneous fat at 24months, but not with central-to-total subcutaneous fat ratio. No associations were present for maternal total or period-specific gestational weight gain with infant fat. CONCLUSION: Maternal body mass index was positively associated with infant body mass index and total subcutaneous fat in late infancy. Maternal total and period-specific gestational weight gain were not associated with infant body fat mass measures.

Development of subcutaneous fat in Spanish and Latin American children and adolescents: Reference values for biceps, triceps, subscapular and suprailiac skinfolds.

Subcutaneous fat skinfolds represent a reliable assessment instrument of adiposity status. This study provides current percentile references for four subcutaneous skinfolds (biceps, triceps, subscapular, suprailiac) applicable to children and adolescents in Spain and in Latin American countries where data are scarce. The design consisted of a cross-sectional multicenter study performed with identical methods in 5 countries (Argentina, Cuba, Mexico, Spain and Venezuela). Total sample comprised 9163 children and youths (boys 4615 - girls 4548) aged 6-18 years, healthy and without apparent pathologies. Percentiles 3, 5, 10, 25, 50, 75, 90, 95 and 97 were calculated by the LMS method. Sexual dimorphism was assessed using the t-test and age differences with ANOVA. Normalized growth percentile references were obtained according to sex and age for each skinfold. The mean values of four skinfolds were significantly greater in girls than boys (p<0.001) and, in both sexes, all skinfolds show statistical differences through age (p<0.001) with different magnitudes. Except triceps in girls, peaks between 11 and 12 years of age are more noticeable in boys than in girls. Although the general model of growth is known, the skinfold measurements show variability among populations and differences of magnitude are presented according to the analyzed population. Therefore, these age and sex-specific reference percentile values for biceps, triceps, subscapular and suprailiac skinfolds, derived from a large sample of Spanish and Latin American children and adolescents, are a useful tool for adiposity diagnosis in this population for which no reference values were available.

Receptor for hyaluronan mediated motility (RHAMM/HMMR) is a novel target for promoting subcutaneous adipogenesis.

Hyaluronan, CD44 and the Receptor for Hyaluronan-Mediated Motility (RHAMM, gene name HMMR) regulate stem cell differentiation including mesenchymal progenitor differentiation. Here, we show that CD44 expression is required for subcutaneous adipogenesis, whereas RHAMM expression suppresses this process. We designed RHAMM function blocking peptides to promote subcutaneous adipogenesis as a clinical and tissue engineering tool. Adipogenic RHAMM peptides were identified by screening for their ability to promote adipogenesis in culture assays using rat bone marrow mesenchymal stem cells, mouse pre-adipocyte cell lines and primary human subcutaneous pre-adipocytes. Oil red O uptake into fat droplets and adiponectin production were used as biomarkers of adipogenesis. Positive peptides were formulated in either collagen I or hyaluronan (Orthovisc) gels then assessed for their adipogenic potential in vivo following injection into dorsal rat skin and mammary fat pads. Fat content was quantified and characterized using micro CT imaging, morphometry, histology, RT-PCR and ELISA analyses of adipogenic gene expression. Injection of screened peptides increased dorsal back subcutaneous fat pad area (208.3 ± 10.4 mm2versus control 84.11 ± 4.2 mm2; p < 0.05) and mammary fat pad size (45 ± 11 mg above control background, p = 0.002) in female rats. This effect lasted >5 weeks as detected by micro CT imaging and perilipin 1 mRNA expression. RHAMM expression suppresses while blocking peptides promote expression of PPARγ, C/EBP and their target genes. Blocking RHAMM function by peptide injection or topical application is a novel and minimally invasive method for potentially promoting subcutaneous adipogenesis in lipodystrophic diseases and a complementary tool to subcutaneous fat augmentation techniques.